Engine will not start

2003 MERCEDES BENZ C230
165,000 MILES • 1.8L • 4 CYL • FWD • AUTOMATIC
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TRCO
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The engine started out surging, no power and stalling when idling. A mechanic suggested using MAF sensor cleaner. I bought a can and sprayed the MAF sensor. I did not remove the sensor. I let it sit for 30 minutes then tried to start it and it would not start, but seemed to be backfiring through intake, but not loudly. I pulled the plugs and they were not fouled. I put about a teaspoon of gas in the intake and that made no difference. I then decided I somehow ruined the MAF sensor, so I bought another one. I installed the new one and it still will not start/no changes. I pulled the connector to the MAF sensor and cleaned with electronics cleaner, did not help.
I am not sure what to do at this point.
Nov 23, 2014 at 3:53 PM
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CADIEMAN
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YOU NEED TO CHECK FOR A CLOGGED CONVERTER. REMOVE THE FRONT OF THE CONVERTER.THEN SEE IF IT WILL START AND IDOL.
IF YOU CAN'T REMOVE
THE CONVERTER REMOVE THE MASS AIR FLOW SENSOR AND TRY AND START IT.




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Nov 23, 2014 at 5:12 PM
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TRCO
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Not to argue, but I really don't think the converter is the problem since the engine ran, though poorly, until I sprayed the MAF sensor. I don't see the connection. Perhaps you can explain.

The mass airflow sensor is in line with the intake plumbing. If I remove it, there is just a tube left from the throttle body. I did try unplugging the sensor and this made no difference. Please keep in mind that I just replaced the MAF sensor.

I really do appreciate your thoughts on this and don't want to come across as a know it all, so please don't take it that way and as a matter of fact, if you have any other ideas, I am all ears.
Thanks.
Nov 23, 2014 at 5:36 PM
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CADIEMAN
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NO POWER AND STALLING IS CAUSED BY:
1) A RESTRICTED EXHAUST
2) LOW FUEL PRESSURE ( YOU CAN RENT A GAUGE FOR CHECKING IT AT THE PARTS STORE )
3) CHECK TO MAKE SURE ALL THE CYLINDERS ARE GETTING SPARK. START HERE OK
Nov 24, 2014 at 6:41 AM
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CADIEMAN
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try
SPRAYING THROTTLE BODY CLEANER IN THE INTAKE WILL IT START?
Nov 24, 2014 at 7:37 AM
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TRCO
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the engine will not start (see 1st post)
Nov 25, 2014 at 3:28 PM
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TRCO
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I sprayed gas and MAF cleaner, will not start. Checked coils for power and there IS power to the coils. So there is power to the ignition coils, the plugs are clean and there is fuel to the cylinders.

Again, I just don't understand why cleaning the MAF Sensor would cause the engine to not start. I can understand why cleaning would not help, but why would it cause it to not start, even after replacing the MAF Sensor?
Nov 25, 2014 at 3:33 PM
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CADIEMAN
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Check for spark at the plug wires with a test light. Something happened when you tried to cleaned that sensor. Check for cracked vacuum hoses also. I'm trying to help you the best way i can without being there.some times that is hard.i'm sorry
Nov 26, 2014 at 12:11 AM
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TRCO
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Okay, sorry if I am coming across a bit harsh. I really do appreciate your input. I will try your suggestions and let you know. I just need to get this thing going so I can trade it in and get my daughter a decent/safe vehicle to drive.
Can't find any vacuum leaks and the spark plugs are firing.
The backfiring back thru the intake concerns me. Could it be the camshaft position sensor? I am going to check to make sure the wiring is connected to it, maybe that is the problem.
Nov 26, 2014 at 4:12 AM
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CADIEMAN
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The only thing it can be is an internal engine problem sorry to say. The backfiring through the intake supports this. It sounds like a timing issue. It may be a chain or gear has lost a tooth.
Nov 26, 2014 at 4:02 PM
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TRCO
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I've done some research and found the symptoms match a bad Camshaft Position Sensor. It has a three pin connector. Is there a way to check to see if the sensor itself is bad with an ohmmeter? I want to exhaust all of the easy things before I tackle the timing chain.
Nov 28, 2014 at 4:27 PM
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KASEKENNY
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Sounds like a couple issues going on here. Let's start with what sounds like the most immediate which is the not starting.

Your engine needs three things to start. Ignition/spark at the right time, fuel, and compression. The backfiring sounds like a timing issue so we need to start with spark. I assume you have spark due to the backfiring but not at the right time. It also appears you have fuel because using the fuel in the intake did not make a difference. Let's assume for now that nothing happened to the compression as this seems to have just started. However, a compression test could show a timing issue if it is out far enough.

This means we need to tackle the timing first. This means we need to check for codes and see what is there. I am not suggesting that timing is off due to it being a timing chain and not a belt. Plus nothing seemed to happen to cause this.

I am thinking there is a variable timing issue. If this is the case there will be codes. Which is why we need to start with codes.

Here are guides that will help get this process started:

https://www.2carpros.com/articles/how-camshaft-variable-valve-timing-works

https://www.2carpros.com/articles/car-cranks-but-wont-start

https://www.2carpros.com/articles/engine-surges

Lastly I attached the info about the cam position sensor because it could be as simple as a sensor or more complicated like a cam phaser.

Let me know codes and we can go from there. Thanks
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